JP2007052209A - Photosensitive resin composition, spacer for display panel and display panel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a photosensitive resin composition for spacers having a satisfactory process margin, capable of suppressing contamination of a kiln, a photomask, etc., due to sublimation of a photopolymerization initiator component, causing no in-liquid foreign substance, and capable of easily forming spacers excellent in the shape of a cross section and in various performances such as compressive strength, rubbing resistance and adhesion to a transparent substrate, spacers formed of the composition, a method for forming the same, and a liquid crystal display panel having the spacers. <P>SOLUTION: The photosensitive resin composition contains as essential components [A] a copolymer of (a1) an unsaturated carboxylic acid and/or an unsaturated carboxylic acid anhydride, (a2) a specific monomer having an oxetanyl group, and (a3) an ethylenically unsaturated compound other than the components (a1) and (a2), [B] a polymerizable compound having an ethylenically unsaturated bond, and [C] a specific photopolymerization initiator. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a photosensitive resin composition, a display panel spacer, and a display panel, and more particularly, a photosensitive resin composition suitable as a material for forming a spacer used in a display panel such as a liquid crystal display panel or a touch panel. And a display panel spacer formed from the composition, and a display panel comprising the spacer.

Conventionally, liquid crystal display panels use spacer particles such as glass beads and plastic beads having a predetermined particle size in order to keep the distance (cell gap) between two substrates constant. Since particles are randomly distributed on a transparent substrate such as a glass substrate, the presence of spacer particles in the pixel formation region may cause a phenomenon of spacer particle reflection or scattering of incident light, resulting in a contrast of the liquid crystal panel. There was a problem of lowering.
In order to solve these problems, a method of forming a spacer by photolithography has been adopted. In this method, a photosensitive resin composition is applied onto a substrate, exposed to ultraviolet rays through a predetermined mask, and then developed to form dot-like or stripe-like spacers. Since the spacer can be formed only at a predetermined place, the above-described problem is basically solved.
In recent years, from the viewpoint of manufacturing cost, the number of cases where it is used in the same process as a conventionally used material has increased. In such cases, the photosensitive resin composition for interlayer insulating films and the photosensitive resin composition for spacers are often used under conditions that deviate from the optimum process conditions, particularly when the prebake temperature deviates from the optimum conditions. Cannot be obtained or the pattern is peeled off. Further, as the substrate becomes larger, the warpage of the substrate during proximity baking becomes more prominent, and the temperature distribution occurs even on the same substrate, so that the photosensitive resin composition for an interlayer insulating film having a wider process margin, and There is a need for a photosensitive resin composition for spacers.
Therefore, in order to solve such a problem, the present applicant has already disclosed, in Patent Document 1, a sufficient process margin that can cope with changes in process conditions, and heat resistance necessary as an interlayer insulating film and spacer, A photosensitive resin composition capable of giving a cured product having both chemical resistance, transparency and hardness has been clarified.

JP 2001-302712 A

In recent years, the size of the mother glass substrate has been increased from about 680 × 880 mm to about 1870 × 2200 mm due to the increase in the area of the liquid crystal display element and the improvement of productivity. In the spacer formation step, the spacer-forming photosensitive resin composition is usually applied to a transparent substrate, baked on a hot plate to remove the solvent, and then exposed to light and developed to form the spacer. However, as the substrate becomes larger, the photopolymerization initiator component in the photosensitive resin composition sublimates during spacer formation, and the problem of contaminating the baking furnace and photomask causes a decrease in production tact and an increase in production cost. It is a concern.
Further, the present applicant has disclosed in Patent Document 2 1- (2-bromo-4-morpholinophenyl) -2-benzyl-2-dimethylaminobutan-1-one as a photopolymerization initiator of the photosensitive resin composition or By using a bromine-substituted acetophenone-based photopolymerization initiator such as 1- (3-bromo-4-morpholinophenyl) -2-benzyl-2-dimethylaminobutan-1-one, This indicates that contamination of the baking furnace and exhaust duct due to sublimation, clogging of a filter provided in the development line when the developer is repeatedly used, and the like can be reduced.

JP 2001-235617 A

The photosensitive resin composition used for forming the spacer usually contains a polymerizable unsaturated compound such as (meth) acrylic acid ester or a compound having a thermal crosslinking group such as an epoxy group. In order to prevent the crosslinking reaction, the composition solution is often stored at a temperature lower than room temperature. However, the bromine-substituted acetophenone compound described in Patent Document 2 often recrystallizes and precipitates during storage at a low temperature, or the temperature of the composition solution in which the bromine-substituted acetophenone compound is recrystallized at room temperature. However, the recrystallized component is difficult to re-dissolve and remains as a foreign substance in the liquid during the spacer formation process, which may cause unevenness of the stripes on the substrate and a decrease in sensitivity. high.

  It is an object of the present invention to have a sufficient process margin, suppress contamination of a baking furnace, a photomask, etc. due to sublimation of a photopolymerization initiator component, generate no foreign matter in the liquid, and have a sectional shape, compressive strength, and rubbing. Photosensitive resin composition for spacer capable of easily forming a spacer excellent in various properties such as durability and adhesion to a transparent substrate, a spacer formed therefrom, a method for forming the spacer, and a liquid crystal display panel having the spacer Is to provide.

According to the present invention, the problem is firstly
[A] (a1) unsaturated carboxylic acid and / or unsaturated carboxylic acid anhydride,
(A2) a monomer represented by the following general formula (I) or general formula (II),

［ここで、一般式（Ｉ）および一般式（II）のＲは水素原子または炭素数１〜４のアルキル基であり、Ｒ₁は水素原子または炭素数１〜４のアルキル基であり、Ｒ₂、Ｒ₃、Ｒ₄およびＲ₅はそれぞれ独立に水素原子、フッ素原子、炭素数１〜４のアルキル基、フェニル基、または炭素数１〜４のパーフロロアルキル基であり、そしてｎは１〜６の整数である。］
ならびに、
（ａ３）前記（ａ１）および（ａ２）以外のエチレン性不飽和化合物の共重合体、
［Ｂ］エチレン性不飽和結合を有する重合性化合物、ならびに
［Ｃ］下記一般式（III）で表される化合物を必須成分とする光重合開始剤を含有することを特徴とする感光性樹脂組成物、からなる。

[Wherein, R in the general formulas (I) and (II) is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms; R ₁ is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms; ₂ , R ₃ , R ₄ and R ₅ are each independently a hydrogen atom, a fluorine atom, an alkyl group having 1 to 4 carbon atoms, a phenyl group, or a perfluoroalkyl group having 1 to 4 carbon atoms, and n is 1 It is an integer of ~ 6. ]
And
(A3) a copolymer of an ethylenically unsaturated compound other than (a1) and (a2),
[B] A photosensitive resin composition comprising a polymerizable compound having an ethylenically unsaturated bond, and [C] a photopolymerization initiator having a compound represented by the following general formula (III) as an essential component It consists of things.

［一般式（III）において、Ｒ₆は炭素数１〜１２の直鎖状、分岐状もしくは環状のアルキル基を示し、Ｒ_７及びＲ_８は相互に独立に水素原子；炭素数１〜１２の直鎖状、分岐状もしくは環状のアルキル基またはベンジル基を示し、Ｒ_９、Ｒ_１０、Ｒ_1２及びＲ_1３は相互に独立に水素原子;ハロゲン原子；炭素数１〜１２の直鎖状、分岐状もしくは環状のアルキル基または炭素数１〜４の直鎖状もしくは分岐状のアルコキシル基を示し、Ｒ_１１は、ハロゲン原子；炭素数１〜１２の直鎖状、分岐状もしくは環状のアルキル基；水酸基および炭素数１〜４の直鎖状もしくは分岐状のアルコキシル基の群から選ばれる置換基で置換された炭素数１〜１２の直鎖状、分岐状もしくは環状のアルキル基；炭素数１〜４の直鎖状もしくは分岐状のアルコキシル基；または水酸基および炭素数１〜４の直鎖状もしくは分岐状のアルコキシル基の群から選ばれる置換基で置換された炭素数２〜４の直鎖状もしくは分岐状のアルコキシル基を示す。］

[In the general formula (III), R ₆ represents a linear, branched or cyclic alkyl group having 1 to 12 carbon atoms, R ₇ and R ₈ are independently a hydrogen atom; A linear, branched or cyclic alkyl group or a benzyl group, wherein R ₉ , R ₁₀ , R ₁₂ and R ₁₃ are each independently a hydrogen atom; a halogen atom; a linear or branched group having 1 to 12 carbon atoms A linear or branched alkyl group having 1 to 4 carbon atoms or a linear or branched alkoxyl group having 1 to 4 carbon atoms, and R ₁₁ is a halogen atom; a linear, branched or cyclic alkyl group having 1 to 12 carbon atoms; A linear, branched or cyclic alkyl group having 1 to 12 carbon atoms substituted with a substituent selected from the group consisting of a hydroxyl group and a linear or branched alkoxyl group having 1 to 4 carbon atoms; 4 linear or branched al It shows the or hydroxyl and straight-chain or branched straight-chain or branched alkoxy group having 2 to 4 carbon atoms which is substituted with a substituent selected from the group of alkoxy group having 1 to 4 carbon atoms; cyclohexyl group. ]

The present invention secondly comprises a spacer formed from the spacer-forming photosensitive resin composition.

Thirdly, the present invention comprises a spacer forming method characterized by including at least the following steps (a) to (d).
(A) a step of forming a coating of the above-mentioned radiation-sensitive resin composition for forming a spacer on a substrate;
(B) exposing at least a part of the coating;
(C) a step of developing the coated film after exposure, and (d) a step of heating the coated film after development.

  The present invention fourthly comprises a liquid crystal display panel comprising the spacer.

Hereinafter, the present invention will be described in detail.
Hereinafter, each component of the spacer-forming photosensitive resin composition of the present invention (hereinafter simply referred to as “photosensitive resin composition (A)”) will be described in detail.
-Copolymer [A]-
[A] component in the photosensitive resin composition copolymer of this invention is manufactured by radically polymerizing compound (a1), compound (a2), and compound (a3) in presence of a polymerization initiator in a solvent. can do.

  Among the components constituting the copolymer [A], (a1) an ethylenically unsaturated carboxylic acid and / or an ethylenically unsaturated carboxylic acid anhydride (hereinafter referred to as “unsaturated carboxylic acid monomer”) Examples of (a1) "include monocarboxylic acids such as acrylic acid, methacrylic acid, crotonic acid, 2-methacryloyloxyethyl succinic acid, 2-methacryloyloxyethyl hexahydrophthalic acid; maleic acid, fumaric acid Examples thereof include dicarboxylic acids such as acid, citraconic acid, mesaconic acid, and itaconic acid; and anhydrides of the dicarboxylic acid.

Among these unsaturated carboxylic acid monomers (a1), acrylic acid, methacrylic acid, maleic anhydride are available from the viewpoints of copolymerization reactivity, solubility of the resulting copolymer in an alkaline aqueous solution and easy availability. 2-methacryloyloxyethyl hexahydrophthalic acid and the like are preferable.
In the photosensitive resin composition (a), the unsaturated carboxylic acid monomer (a1) can be used alone or in admixture of two or more.

  In the copolymer [A], the content of the repeating unit derived from the unsaturated carboxylic acid monomer (a1) is preferably 5 to 50% by weight, more preferably 10 to 40% by weight, and particularly preferably 15%. ~ 30% by weight. In this case, when the content of the repeating unit derived from the unsaturated carboxylic acid monomer (a1) is less than 5% by weight, the solubility in an alkaline aqueous solution tends to decrease, whereas when it exceeds 40% by weight. There is a possibility that the solubility in an aqueous alkali solution becomes too large.

  Examples of the compound (a2) represented by the general formula (I) include 3- (methacryloyloxymethyl) oxetane, 3- (methacryloyloxymethyl) -3-ethyloxetane, and 3- (methacryloyloxymethyl) -2-methyloxetane. 3- (methacryloyloxymethyl) -2-trifluoromethyloxetane, 3- (methacryloyloxymethyl) -2-pentafluoroethyloxetane, 3- (methacryloyloxymethyl) -2-phenyloxetane, 3- (methacryloyloxymethyl) ) -2,2-difluorooxetane, 3- (methacryloyloxymethyl) -2,2,4-trifluorooxetane, 3- (methacryloyloxymethyl) -2,2,4,4-tetrafluorooxetane, 3- (Methacryloyloxyethyl) oxetane 3- (methacryloyloxyethyl) -3-ethyloxetane, 2-ethyl-3- (methacryloyloxyethyl) oxetane, 3- (methacryloyloxyethyl) -2-trifluoromethyloxetane, 3- (methacryloyloxyethyl) -2 -Pentafluoroethyl oxetane, 3- (methacryloyloxyethyl) -2-phenyloxetane, 2,2-difluoro-3- (methacryloyloxyethyl) oxetane, 3- (methacryloyloxyethyl) -2,2,4-trifluoro Methacrylic acid esters such as oxetane and 3- (methacryloyloxyethyl) -2,2,4,4-tetrafluorooxetane;

3- (acryloyloxymethyl) oxetane, 3- (acryloyloxymethyl) -3-ethyloxetane, 3- (acryloyloxymethyl) -2-methyloxetane, 3- (acryloyloxymethyl) -2-trifluoromethyloxetane, 3- (acryloyloxymethyl) -2-pentafluoroethyloxetane, 3- (acryloyloxymethyl) -2-phenyloxetane, 3- (acryloyloxymethyl) -2,2-difluorooxetane, 3- (acryloyloxymethyl) ) -2,2,4-trifluorooxetane, 3- (acryloyloxymethyl) -2,2,4,4-tetrafluorooxetane, 3- (acryloyloxyethyl) oxetane, 3- (acryloyloxyethyl) -3 -Ethyloxetane, 2-ethyl-3 (Acryloyloxyethyl) oxetane, 3- (acryloyloxyethyl) -2-trifluoromethyloxetane, 3- (acryloyloxyethyl) -2-pentafluoroethyloxetane, 3- (acryloyloxyethyl) -2-phenyloxetane, 2,2-difluoro-3- (acryloyloxyethyl) oxetane, 3- (acryloyloxyethyl) -2,2,4-trifluorooxetane, 3- (acryloyloxyethyl) -2,2,4,4-tetra And acrylic acid esters such as fluorooxetane.

  Examples of the compound (a2) represented by the general formula (II) include 2- (methacryloyloxymethyl) oxetane, 2-methyl-2- (methacryloyloxymethyl) oxetane, and 3-methyl-2- (methacryloyloxymethyl) oxetane. 4-methyl-2- (methacryloyloxymethyl) oxetane, 2- (methacryloyloxymethyl) -2-trifluoromethyloxetane, 2- (methacryloyloxymethyl) -3-trifluoromethyloxetane, 2- (methacryloyloxymethyl) ) -4-Trifluoromethyloxetane, 2- (methacryloyloxymethyl) -2-pentafluoroethyl oxetane, 2- (methacryloyloxymethyl) -3-pentafluoroethyloxetane, 2- (methacryloyloxymethyl) -4-pentafluoro Ethyl oxetane, 2- (methacryloyloxymethyl) -2-phenyloxetane, 2- (methacryloyloxymethyl) -3-phenyloxetane, 2- (methacryloyloxymethyl) -4-phenyloxetane, 2,3-difluoro-2- (Methacryloyloxymethyl) oxetane, 2,4-difluoro-2- (methacryloyloxymethyl) oxetane, 3,3-difluoro-2- (methacryloyloxymethyl) oxetane, 3,4-difluoro-2- (methacryloyloxymethyl) Oxetane, 4,4-difluoro-2- (methacryloyloxymethyl) oxetane, 2- (methacryloyloxymethyl) -3,3,4-trifluorooxetane, 2- (methacryloyloxymethyl) -3,4,4-tri Fluoroxetane, 2- (me Tacriroyloxymethyl) -3,3,4,4-tetrafluorooxetane,

2- (methacryloyloxyethyl) oxetane, 2- (2- (2-methyloxetanyl)) ethyl methacrylate, 2- (2- (3-methyloxetanyl)) ethyl methacrylate, 2- (methacryloyloxyethyl) -2-methyl Oxetane, 2- (methacryloyloxyethyl) -4-methyloxetane, 2- (methacryloyloxyethyl) -2-trifluoromethyloxetane, 2- (methacryloyloxyethyl) -3-trifluoromethyloxetane, 2- (methacryloyloxy) Ethyl) -4-trifluoromethyloxetane, 2- (methacryloyloxyethyl) -2-pentafluoroethyloxetane, 2- (methacryloyloxyethyl) -3-pentafluoroethyloxetane, 2- (methacryloyloxyethyl) -4- N-tafluoroethyloxetane, 2- (methacryloyloxyethyl) -2-phenyloxetane, 2- (methacryloyloxyethyl) -3-phenyloxetane, 2- (methacryloyloxyethyl) -4-phenyloxetane, 2,3-difluoro- 2- (methacryloyloxyethyl) oxetane, 2,4-difluoro-2- (methacryloyloxyethyl) oxetane, 3,3-difluoro-2- (methacryloyloxyethyl) oxetane, 3,4-difluoro-2- (methacryloyloxy) Ethyl) oxetane, 4,4-difluoro-2- (methacryloyloxyethyl) oxetane, 2- (methacryloyloxyethyl) -3,3,4-trifluorooxetane, 2- (methacryloyloxyethyl) -3,4,4 -Trifluorooxeta , 2- (methacryloyloxyethyl) 3,3,4,4 methacrylic acid esters of tetrafluoroethane oxetane, and the like;

2- (acryloyloxymethyl) oxetane, 2-methyl-2- (acryloyloxymethyl) oxetane, 3-methyl-2- (acryloyloxymethyl) oxetane, 4-methyl-2- (acryloyloxymethyl) oxetane, 2- (Acryloyloxymethyl) -2-trifluoromethyloxetane, 2- (acryloyloxymethyl) -3-trifluoromethyloxetane, 2- (acryloyloxymethyl) -4-trifluoromethyloxetane, 2- (acryloyloxymethyl) 2-Pentafluoroethyl oxetane, 2- (acryloyloxymethyl) -3-pentafluoroethyl oxetane, 2- (acryloyloxymethyl) -4-pentafluoroethyl oxetane, 2- (acryloyloxymethyl) -2-phenyloxet 2- (acryloyloxymethyl) -3-phenyloxetane, 2- (acryloyloxymethyl) -4-phenyloxetane, 2,3-difluoro-2- (acryloyloxymethyl) oxetane, 2,4-difluoro-2 -(Acryloyloxymethyl) oxetane, 3,3-difluoro-2- (acryloyloxymethyl) oxetane, 3,4-difluoro-2- (acryloyloxymethyl) oxetane, 4,4-difluoro-2- (acryloyloxymethyl) ) Oxetane, 2- (acryloyloxymethyl) -3,3,4-trifluorooxetane, 2- (acryloyloxymethyl) -3,4,4-trifluorooxetane, 2- (acryloyloxymethyl) -3,3 , 4,4-tetrafluorooxetane,

2- (acryloyloxyethyl) oxetane, 2- (2- (2-methyloxetanyl)) ethyl methacrylate, 2- (2- (3-methyloxetanyl)) ethyl methacrylate, 2- (acryloyloxyethyl) -2-methyl Oxetane, 2- (acryloyloxyethyl) -4-methyloxetane, 2- (acryloyloxyethyl) -2-trifluoromethyloxetane, 2- (acryloyloxyethyl) -3-trifluoromethyloxetane, 2- (acryloyloxy) Ethyl) -4-trifluoromethyloxetane, 2- (acryloyloxyethyl) -2-pentafluoroethyloxetane, 2- (acryloyloxyethyl) -3-pentafluoroethyloxetane, 2- (acryloyloxyethyl) -4- Pentafluoroethyl Xetane, 2- (acryloyloxyethyl) -2-phenyloxetane, 2- (acryloyloxyethyl) -3-phenyloxetane, 2- (acryloyloxyethyl) -4-phenyloxetane, 2,3-difluoro-2- ( Acryloyloxyethyl) oxetane, 2,4-difluoro-2- (acryloyloxyethyl) oxetane, 3,3-difluoro-2- (acryloyloxyethyl) oxetane, 3,4-difluoro-2- (acryloyloxyethyl) oxetane 4,4-Difluoro-2- (acryloyloxyethyl) oxetane, 2- (acryloyloxyethyl) -3,3,4-trifluorooxetane, 2- (acryloyloxyethyl) -3,4,4-trifluoro Oxetane, 2- (acryloyloxyethyl)- , 3,4,4 acrylic acid esters such as tetrafluoroethane oxetane and the like.

  Among these, 3- (methacryloyloxymethyl) oxetane, 3- (methacryloyloxymethyl) -2-trifluoromethyloxetane, 3- (methacryloyloxymethyl) -2-phenyloxetane, 2- (methacryloyloxymethyl) oxetane, The photosensitive resin composition from which 2- (methacryloyloxymethyl) -4-trifluoromethyloxetane and the like are obtained has a wide process margin and is preferably used from the viewpoint of enhancing the chemical resistance of the resulting spacer. These may be used alone or in combination.

  The copolymer [A] used in the present invention preferably contains 0 to 70% by weight, particularly preferably 3 to 50% by weight, of structural units derived from the compound (a2). When this structural unit is less than 3% by weight, the heat resistance of the copolymer [A] tends to decrease, whereas when it exceeds 70% by weight, the copolymer [A] is difficult to dissolve in the alkaline aqueous solution. .

Further, (a3) other ethylenically unsaturated compounds (hereinafter simply referred to as “other monomers”) include, for example, alkyl acrylates such as methyl acrylate and i-propyl acrylate; methacrylic acid Methacrylic acid alkyl esters such as methyl, ethyl methacrylate, n-butyl methacrylate, sec-butyl methacrylate, t-butyl methacrylate; cyclohexyl acrylate, 2-methylcyclohexyl acrylate, tricycloacrylate [5.2. 1.0 ^2,6] decan-8-yl, acrylic acid 2- (tricyclo [5.2.1.0 ^2,6] decan-8-yloxy) ethyl, acrylic San'abura cyclic ester such as isobornyl acrylate Class: cyclohexyl methacrylate, 2-methylcyclohexyl methacrylate, trisyl methacrylate [5.2.1.0 ^2,6] decan-8-yl methacrylate, 2 (tricyclo [5.2.1.0 ^2,6] decan-8-yloxy) ethyl, methacrylate such as methacrylic acid isobornyl Acid alicyclic esters; aryl esters or aralkyl esters of acrylic acid such as phenyl acrylate and benzyl acrylate; aryl esters or aralkyl esters of methacrylic acid such as phenyl methacrylate and benzyl methacrylate; diethyl maleate and fumarate Dicarboxylic acid dialkyl esters such as diethyl acrylate and diethyl itaconate; Methacrylic acid hydroxyalkyl esters such as 2-hydroxyethyl methacrylate and 2-hydroxypropyl methacrylate; Tetrahydrofurfuryl methacrylate, Tetrahydrofuryl methacrylate Unsaturated hetero 5- and 6-membered methacrylic acid esters containing one oxygen atom such as tetrahydrofupyran-2-methyl methacrylate; glycidyl acrylate, 2-methylglycidyl acrylate, 3,4-epoxybutyl acrylate, acrylic Acrylic acid epoxy alkyl esters such as acid 6,7-epoxyheptyl and 3,4-epoxycyclohexyl acrylate; glycidyl methacrylate, 2-methylglycidyl methacrylate, 3,4-epoxybutyl methacrylate, 6,7 methacrylate -Epoxy heptyl, methacrylic acid epoxy alkyl esters such as 3,4-epoxycyclohexyl methacrylate; glycidyl α-ethyl acrylate, glycidyl α-n-propyl acrylate, glycidyl α-n-butyl acrylate, α-ethyl acrylic Acid 6,7- Α-alkyl acrylic acid epoxy alkyl esters such as poxyheptyl; glycidyl ethers such as o-vinylbenzyl glycidyl ether, m-vinylbenzyl glycidyl ether, p-vinylbenzyl glycidyl ether; styrene, α-methylstyrene, m-methylstyrene , Vinyl aromatic compounds such as p-methylstyrene and p-methoxystyrene; phenylmaleimide, cyclohexylmaleimide, benzylmaleimide, N-succinimidyl-3-maleimidobenzoate, N-succinimidyl-4-maleimidobutyrate, N-succinimidyl-6 -Dicarbonylimide derivatives such as maleimidocaproate, N-succinimidyl-3-maleimidopropionate, N- (9-acridinyl) maleimide; 1,3-butadiene Emissions, isoprene, 2,3-dimethyl-1,3-addition of the conjugated diene compound such as butadiene, can be acrylonitrile, methacrylonitrile, acrylamide, methacrylamide, vinyl chloride, be mentioned vinylidene chloride, vinyl acetate and the like.

Among these other monomers, 2-methylcyclohexyl acrylate, hydroxyethyl methacrylate, tricyclomethacrylate [5.2. From the viewpoint of copolymerization reactivity and solubility of the resulting copolymer in an alkaline aqueous solution. 1.0 ^2,6 ] decan-8-yl, styrene, glycidyl methacrylate, tetrahydrofurfuryl methacrylate, 1,3-butadiene and the like are preferable.
In the copolymer [A], other monomers can be used alone or in admixture of two or more.

  The copolymer [A] used in the present invention preferably contains 10 to 70% by weight, more preferably 20 to 50% by weight, and particularly preferably 30 to 50% by weight of the structural unit derived from the compound (a3). Contains. In this case, when the structural unit is less than 10% by weight, the storage stability of the copolymer [A] tends to be reduced, whereas when it exceeds 70% by weight, the copolymer [A] is dissolved in the alkaline aqueous solution. It becomes difficult to do.

As described above, the copolymer [A] used in the present invention has a carboxyl group and / or a carboxylic anhydride group and an oxetanyl group, and has appropriate solubility in an alkaline aqueous solution, It can be easily cured by heating without using a special curing agent.
The photosensitive resin composition containing the copolymer [A] described above exhibits good alkali solubility during development and can easily form a spacer having a predetermined pattern.

  Examples of the solvent used for the production of the copolymer [A] include alcohol, ether, glycol ether, ethylene glycol alkyl ether acetate, diethylene glycol, dipropylene glycol, propylene glycol monoalkyl ether, propylene glycol alkyl ether acetate, and propylene glycol. Examples include alkyl ether propionates, aromatic hydrocarbons, ketones and esters.

Specific examples thereof include alcohols such as methanol, ethanol, benzyl alcohol, 2-phenylethyl alcohol, and 3-phenyl-1-propanol;
Ethers such as tetrahydrofuran;
Examples of glycol ethers include ethylene glycol monomethyl ether and ethylene glycol monoethyl ether;
Examples of ethylene glycol alkyl ether acetate include methyl cellosolve acetate, ethyl cellosolve acetate, ethylene glycol monobutyl ether acetate, and ethylene glycol monoethyl ether acetate;
Examples of diethylene glycol include diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, and diethylene glycol ethyl methyl ether.
Examples of dipropylene glycol include dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol dimethyl ether, dipropylene glycol diethyl ether, and dipropylene glycol ethyl methyl ether;
Examples of propylene glycol monoalkyl ethers include propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, propylene glycol monobutyl ether;
As propylene glycol alkyl ether propionate, for example, propylene glycol methyl ether acetate, propylene glycol ethyl ether acetate, propylene glycol propyl ether acetate, propylene glycol butyl ether acetate and the like;
As propylene glycol alkyl ether acetate, for example, propylene glycol methyl ether propionate, propylene glycol ethyl ether propionate, propylene glycol propyl ether propionate, propylene glycol butyl ether propionate, etc .;
Aromatic hydrocarbons such as toluene, xylene, etc .;
Examples of ketones include methyl ethyl ketone, cyclohexanone, 4-hydroxy-4-methyl-2-pentanone, etc .;

Examples of esters include methyl acetate, ethyl acetate, propyl acetate, butyl acetate, ethyl 2-hydroxypropionate, methyl 2-hydroxy-2-methylpropionate, ethyl 2-hydroxy-2-methylpropionate, methyl hydroxyacetate, hydroxy Ethyl acetate, hydroxybutyl acetate, methyl lactate, ethyl lactate, propyl lactate, butyl lactate, methyl 3-hydroxypropionate, ethyl 3-hydroxypropionate, propyl 3-hydroxypropionate, butyl 3-hydroxypropionate, 2-hydroxy -3-methylbutanoate, methyl methoxyacetate, ethyl methoxyacetate, propyl methoxyacetate, butyl methoxyacetate, methyl ethoxyacetate, ethyl ethoxyacetate, propyl ethoxyacetate, butyl ethoxyacetate, propoxy Methyl acetate, ethyl propoxyacetate, propyl propoxyacetate, butyl propoxyacetate, methyl butoxyacetate, ethyl butoxyacetate, propyl butoxyacetate, butylbutoxyacetate, 3-methoxybutyl acetate, methyl 2-methoxypropionate, ethyl 2-methoxypropionate Propyl 2-methoxypropionate, butyl 2-methoxypropionate, methyl 2-ethoxypropionate, ethyl 2-ethoxypropionate, propyl 2-ethoxypropionate, butyl 2-ethoxypropionate, methyl 2-butoxypropionate, Ethyl 2-butoxypropionate, propyl 2-butoxypropionate, butyl 2-butoxypropionate, methyl 3-methoxypropionate, ethyl 3-methoxypropionate, 3-methoxypropionic acid Lopyl, butyl 3-methoxypropionate, methyl 3-ethoxypropionate, ethyl 3-ethoxypropionate, propyl 3-ethoxypropionate, butyl 3-ethoxypropionate, methyl 3-propoxypropionate, ethyl 3-propoxypropionate , Esters of propyl 3-propoxypropionate, butyl 3-propoxypropionate, methyl 3-butoxypropionate, ethyl 3-butoxypropionate, propyl 3-butoxypropionate, butyl 3-butoxypropionate, etc. it can.

Of these, ethylene glycol alkyl ether acetate, diethylene glycol, dipropylene glycol, propylene glycol monoalkyl ether, and propylene glycol alkyl ether acetate are preferred. Among them, diethylene glycol dimethyl ether, diethylene glycol ethyl methyl ether, dipropylene glycol dimethyl ether, dipropylene glycol ethyl Particularly preferred are methyl ether, propylene glycol methyl ether, propylene glycol methyl ether acetate, and 3-methoxybutyl acetate.
The said solvent can be used individually or in mixture of 2 or more types.

The radical polymerization initiator used for the polymerization is not particularly limited, and for example, 2,2′-azobisisobutyronitrile, 2,2′-azobis- (2,4-dimethylvalero). Nitrile), 2,2′-azobis- (4-methoxy-2,4-dimethylvaleronitrile), 4,4′-azobis (4-cyanovaleric acid), dimethyl 2,2′-azobis (2-methylpro) Azo compounds such as pionate), 2,2′-azobis (4-methoxy-2,4-dimethylvaleronitrile); benzoyl peroxide, lauroyl peroxide, t-butylperoxypivalate, 1,1-bis (t-butyl) Peroxy) organic peroxides such as cyclohexane; hydrogen peroxide and the like. Moreover, when using a peroxide as a radical polymerization initiator, it is good also as a redox type initiator combining it and a reducing agent.
These radical polymerization initiators can be used alone or in admixture of two or more.
The copolymer [A] thus obtained may be used in the preparation of the photosensitive resin composition as a solution, or may be separated from the solution and used in the preparation of the photosensitive resin composition.

  The polystyrene-converted weight average molecular weight (hereinafter referred to as “Mw”) of the copolymer [A] by gel permeation chromatography (GPC) is usually 2,000 to 100,000, preferably 5,000 to 50,000. It is. In this case, if the Mw is less than 2,000, the developability and the remaining film rate of the resulting film may be reduced, and the pattern shape, heat resistance, and the like may be impaired. , There is a possibility that the resolution is lowered or the pattern shape is damaged.

-Polymerizable compound [B]-
[B] component in the photosensitive resin composition (A) is a polymerizable compound having an ethylenically unsaturated bond (hereinafter referred to as “polymerizable compound [B]”).
Although it does not specifically limit as polymeric compound [B], Monofunctional, bifunctional, or trifunctional or more (meth) acrylic acid ester has favorable polymerizability, and the intensity | strength of the spacer obtained is good. It is preferable from the viewpoint of improvement.

  Examples of the monofunctional (meth) acrylic acid esters include 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, diethylene glycol monoethyl ether acrylate, diethylene glycol monoethyl ether methacrylate, isobornyl acrylate, isobornyl methacrylate, 3 -Methoxybutyl acrylate, 3-methoxybutyl methacrylate, 2-acryloyloxyethyl-2-hydroxypropyl phthalate, 2-methacryloyloxyethyl-2-hydroxypropyl phthalate, etc. can be mentioned, and commercially available products include, for example, Aronix M -101, M-111, M-114 (manufactured by Toa Gosei Co., Ltd.); KAYARAD TC-110S, TC-120S (manufactured by Nippon Kayaku Co., Ltd.) ; Viscoat 158, mention may be made of the 2311 (manufactured by Osaka Organic Chemical Industry Ltd.) and the like.

  Examples of the bifunctional (meth) acrylic acid esters include ethylene glycol diacrylate, ethylene glycol dimethacrylate, diethylene glycol diacrylate, diethylene glycol dimethacrylate, tetraethylene glycol diacrylate, tetraethylene glycol dimethacrylate, 1,6 -Hexanediol diacrylate, 1,6-hexanediol dimethacrylate, 1,9-nonanediol diacrylate, 1,9-nonanediol dimethacrylate, bisphenoxyethanol full orange acrylate, bisphenoxyethanol full orange methacrylate, etc. As commercial products, for example, Aronix M-210, M-240, M-6200 (manufactured by Toa Gosei Co., Ltd.) , KAYARAD HDDA, the HX-220, (manufactured by Nippon Kayaku Co.) Same R-604, Viscoat 260, the 312, the 335HP (manufactured by Osaka Organic Chemical Industry Ltd.) and the like.

Further, the trifunctional or higher functional (meth) acrylic acid esters include, for example, trimethylolpropane triacrylate, trimethylolpropane trimethacrylate, pentaerythritol triacrylate, pentaerythritol trimethacrylate, pentaerythritol tetraacrylate, pentaerythritol tetramethacrylate. , Dipentaerythritol pentaacrylate, dipentaerythritol pentamethacrylate, dipentaerythritol hexaacrylate, dipentaerythritol hexamethacrylate, tri (2-acryloyloxyethyl) phosphate, tri (2-methacryloyloxyethyl) phosphate, etc. Can do.
In particular, a (meth) acrylate having 9 or more functional groups has an alkylene straight chain and an alicyclic structure, a compound containing two or more isocyanate groups, and a trifunctional, tetrafunctional and 5 functional group containing one or more hydroxyl groups in the molecule. The urethane acrylate compound obtained by making a functional (meth) acrylate compound react is mentioned.
As said commercial item, for example, Aronix M-309, M-400, M-405, M-450, M-7100, M-8030, M-8060, M-8060, TO-1450 (Toa Gosei ( KAYARAD TMPTA, DPHA, DPCA-20, DPCA-30, DPCA-60, DPCA-60, DPCA-120 (manufactured by Nippon Kayaku Co., Ltd.), Biscote 295, 300, 360, GPT, 3PA, 400 (produced by Osaka Organic Chemical Industry Co., Ltd.) and the like. Examples of commercially available products of polyfunctional urethane acrylates having 9 or more functional groups include New Frontier R-1150 (manufactured by Daiichi Kogyo Seiyaku Co., Ltd.), KAYARAD DPHA-40H (manufactured by Nippon Kayaku Co., Ltd.) Is mentioned.

Among these monofunctional, bifunctional, or trifunctional or higher (meth) acrylic acid esters, trifunctional or higher functional (meth) acrylic acid esters are more preferable, and in particular, trimethylolpropane triacrylate, pentaerythritol triacrylate, Pentaerythritol tetraacrylate, dipentaerythritol pentaacrylate and dipentaerythritol hexaacrylate are preferred.
The monofunctional, bifunctional, or trifunctional or higher (meth) acrylic acid esters can be used alone or in combination of two or more.

  In the photosensitive resin composition (A), the amount of the polymerizable compound [B] used is preferably 50 to 200 parts by weight, more preferably 60 to 150 parts by weight, with respect to 100 parts by weight of the copolymer [A]. It is. In this case, if the amount of the polymerizable compound [B] used is less than 50 parts by weight, there is a possibility that a development residue may occur during development. On the other hand, if it exceeds 200 parts by weight, the adhesion of the resulting spacer tends to decrease. .

-Photopolymerization initiator [C]-
The component [C] in the photosensitive resin composition (a) of the present invention comprises a compound represented by the general formula (III) (hereinafter referred to as “Compound 1”) as an essential component.

In the general formula (III), R ₆ , R ₇ , R ₈ , R ₉ ^, R ₁₀ , R ₁₁ , R ₁₂ and R _{13 as} a linear, branched or cyclic alkyl group having 1 to 12 carbon atoms. Is, for example, methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, i-butyl group, sec-butyl group, t-butyl group, n-pentyl group, n-hexyl group, Examples include n-heptyl group, n-octyl group, n-nonyl group, n-decyl group, n-undecyl group, n-dodecyl group, cyclopentyl group, cyclohexyl group and the like.

^{_{Also, R 9, R 10, R}} 11, R 12 _and, as the halogen atom of _{R 13,} for example, a fluorine atom, a chlorine atom, may be mentioned bromine atom.
Examples of the linear or branched alkoxyl group having 1 to 4 carbon atoms of R ₉ ^, R ₁₀ , R ₁₁ , R ₁₂ and R ₁₃ include, for example, a methoxy group, an ethoxy group, and an n-propoxy group. I-propoxy group, n-butoxy group, i-butoxy group, sec-butoxy group, t-butoxy group and the like.

In addition, a linear, branched or cyclic alkyl group having 1 to 12 carbon atoms substituted with a substituent selected from the group consisting of a hydroxyl group of R ₁₁ and a linear or branched alkoxyl group having 1 to 4 carbon atoms. In C 1-4 linear or branched alkoxyl group, for example, R ₉ ^, R ₁₀ , R ₁₁ , R ₁₂ and R ₁₃ linear or branched having 1 to 4 carbon atoms. The thing similar to the group illustrated about the shape-like alkoxyl group can be mentioned.
As the substituent for the substituted, straight-chain, branched or cyclic alkyl group having 1 to 12 carbon atoms of R ₁₁ , for example, a hydroxyl group and a methoxy group are preferable.
Examples of the substituted, straight-chain, branched or cyclic alkyl group having 1 to 12 carbon atoms of R ₁₁ include, for example, R ₉ ^, R ₁₀ , R ₁₁ , R ₁₂ and R ₁₃ having 1 to 12 carbon atoms. Examples thereof are the same as those exemplified for the linear or branched alkyl group.
In the substituted, linear, branched or cyclic alkyl group having 1 to 12 carbon atoms represented by R ₁₁ , one or more substituents may be present.

In the general formula (III), R ₆ is methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, i-butyl group, sec-butyl group, t-butyl group, n- Pentyl group, n-hexyl group and the like are preferable.
R ₆ and R ₇ are methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, i-butyl group, sec-butyl group, t-butyl group, n-pentyl group. N-hexyl group, n-heptyl group, n-octyl group and the like are preferable.
R ₉ ^, R ₁₀ , R ₁₂ and R ₁₃ are preferably a hydrogen atom, a methyl group, an ethyl group or the like.

Furthermore, as R ₁₁ , methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, i-butyl group, sec-butyl group, t-butyl group, n-pentyl group, n- Hexyl group, n-heptyl group, n-octyl group, n-nonyl group, n-decyl group, n-undecyl group, n-dodecyl group, hydroxymethyl group, 2-hydroxyethyl group, methoxymethoxy group, 2-methoxy An ethoxy group or the like is preferable.

Specific examples of preferred compound (1) in the present invention include
2- (4-methylbenzyl) -2- (dimethylamino) -1- (4-morpholinophenyl) -butan-1-one,
2- (4-ethylbenzoyl) -2- (dimethylamino) -1- (4-morpholinophenyl) -butan-1-one,
2- (4-isopropylbenzyl) -2- (dimethylamino) -1- (4-morpholinophenyl) -butan-1-one,
2- (4-n-butylbenzyl) -2- (dimethylamino) -1- (4-morpholinophenyl) -butan-1-one,
2- (4-isobutylbenzyl) -2- (dimethylamino) -1- (4-morpholinophenyl) -butan-1-one,
2- (4-n-dodecylbenzyl) -2- (dimethylamino) -1- (4-morpholinophenyl) -butan-1-one,
2- (3,4-dimethylbenzyl) -2- (dimethylamino) -1- (4-morpholinophenyl) -butan-1-one,
2- (4-methoxybenzyl) -2- (dimethylamino) -1- (4-morpholinophenyl) -butan-1-one,
2- (4-ethoxybenzyl) -2- (dimethylamino) -1- (4-morpholinophenyl) -butan-1-one,
2- (4-hydroxymethylbenzyl) -2- (dimethylamino) -1- (4-morpholinophenyl) -butan-1-one,
2- (4- [2-methoxyethoxy] -benzyl) -2- (dimethylamino) -1- (4-morpholinophenyl) -butan-1-one,
2- (4- [2-hydroxyethoxy] -benzyl) -2- (dimethylamino) -1- (4-morpholinophenyl) -butan-1-one,
2- (4-n-dodecylbenzyl) -2- (dimethylamino) -1- (4-morpholinophenyl) -octane-1-one,
2- (4-isopropylbenzyl) -2- (dimethylamino) -1- (4-morpholinophenyl) -pentan-1-one,
2- (4-isopropylbenzyl) -2- (butylmethylamino) -1- (4-morpholinophenyl) -butan-1-one,
2- (4-isobutylbenzyl) -2- (butylmethylamino) -1- (4-morpholinophenyl) -pentan-1-one,
2- (4-methylbenzyl) -2- (dioctylamino) -1- (4-morpholinophenyl) -hexane-1-one,
2- (4-butoxybenzyl) -2- (butylmethylamino) -1- (4-morpholinophenyl) -pentan-1-one,
And 2- (4-n-butylbenzyl) -2- (butylmethylamino) -1- (4-morpholinophenyl) -butan-1-one.

Among these compounds (1), 2- (4-methylbenzyl) -2- (dimethylamino) -1- (4-morpholinophenyl) -butan-1-one,
2- (4-ethylbenzyl) -2- (dimethylamino) -1- (4-morpholinophenyl) -butan-1-one,
2- (4-Isopropylbenzyl) -2- (dimethylamino) -1- (4-morpholinophenyl) -butan-1-one and the like are preferable.
The compound (1) is excellent in solubility in a solvent, does not cause foreign matters such as undissolved matter and precipitation, does not cause contamination of a baking furnace or a photomask due to sublimation, and has no missing or missing pattern. It is a component that can form an excellent spacer.
In this invention, a compound (1) can be used individually or in mixture of 2 or more types.

Moreover, in the photosensitive resin composition of this invention, the usage-amount of a compound (1) becomes like this. Preferably it is 5-50 weight part with respect to 100 weight part of [A] copolymers, More preferably, it is 5-30 weight. Part. In this case, when the amount of the compound (1) used is less than 5 parts by weight, the residual film ratio tends to decrease. On the other hand, when it exceeds 50 parts by weight, the solubility of the unexposed part in the alkaline developer tends to decrease. is there.

Moreover, in the photosensitive resin composition of this invention, at least 1 sort (s) of other photoinitiators can be used together with a compound (1).
Examples of the other photopolymerization initiator include an O-acyloxime type compound, a biimidazole compound, a benzoin compound, an acetophenone compound, a benzophenone compound, an α-diketone compound, and an onium as a radiation-sensitive cationic polymerization initiator. Examples thereof include salts and metallocene compounds, and among these, acetophenone compounds, biimidazole compounds, and radiation-sensitive cationic polymerization initiators are preferable.

The O-acyloxime type compound is a component having an effect of further improving sensitivity. Specific examples of O-acyloxime type compounds include 1- [9-ethyl-6-benzoyl-9.H.-carbazol-3-yl] -nonane-1,2-nonane-2-oxime-O-benzo. Art,
1- [9-ethyl-6-benzoyl-9.H.-carbazol-3-yl] -nonane-1,2-nonane-2-oxime-O-acetate,
1- [9-ethyl-6-benzoyl-9.H.-carbazol-3-yl] -pentane-1,2-pentane-2-oxime-O-acetate,
1- [9-ethyl-6-benzoyl-9.H.-carbazol-3-yl] -octane-1-one oxime-O-acetate,
1- [9-ethyl-6- (2-methylbenzoyl) -9.H.-carbazol-3-yl] -ethane-1-one oxime-O-benzoate,
1- [9-ethyl-6- (2-methylbenzoyl) -9.H.-carbazol-3-yl] -ethane-1-one oxime-O-acetate,
1- [9-ethyl-6- (1,3,5-trimethylbenzoyl) -9.H.-carbazol-3-yl] -ethane-1-one oxime-O-benzoate,
1- [9-butyl-6- (2-ethylbenzoyl) -9.H.-carbazol-3-yl] -ethane-1-one oxime-O-benzoate,
1,2-octadione-1- [4- (phenylthio) phenyl] -2- (O-benzoyloxime),
1,2-butanedione-1- [4- (phenylthio) phenyl] -2- (O-benzoyloxime),
1,2-butanedione-1- [4- (phenylthio) phenyl] -2- (O-acetyloxime),
1,2-octadione-1- [4- (methylthio) phenyl] -2- (O-benzoyloxime),
1,2-octadion-1- [4- (phenylthio) phenyl] -2- (O- (4-methylbenzoyloxime)) and the like.

Of these O-acyloxime types, in particular 1- [9-ethyl-6- (2-methylbenzoyl) -9.H.-carbazol-3-yl] -ethane-1-one oxime-O-acetate, 1 , 2-octadion-1- [4- (phenylthio) phenyl] -2- (O-benzoyloxime) is preferred.
In the present invention, the O-acyloxime type compounds can be used alone or in admixture of two or more.

  In the present invention, in the photosensitive resin composition (i), the total amount of the O-acyloxime type compound is preferably 1 to 30 parts by weight, more preferably 100 parts by weight of the polymerizable compound [B]. 2 to 20 parts by weight. In this case, if the amount of the O-acyloxime compound used is less than 1 part by weight, the remaining film ratio tends to decrease during development. There is a tendency for solubility to decrease.

  Furthermore, as other polymerization initiators other than the O-acyloxime type photopolymerization initiator, for example, biimidazole compounds, benzoin compounds, acetophenone compounds, benzophenone compounds, α-diketone compounds, radiation-sensitive cationic polymerization Examples of the initiator include onium salts and metallocene compounds. Among these, acetophenone compounds, biimidazole compounds, and radiation-sensitive cationic polymerization initiators are preferable.

Examples of the acetophenone compounds include α-hydroxy ketone compounds, α-amino ketone compounds, and other compounds.
Specific examples of the α-hydroxyketone compound include 1-phenyl-2-hydroxy-2-methylpropan-1-one, 1- (4-i-propylphenyl) -2-hydroxy-2-methylpropane- 1-one, 4- (2-hydroxyethoxy) phenyl- (2-hydroxy-2-propyl) ketone, 1-hydroxycyclohexyl phenyl ketone and the like can be mentioned, and specific examples of the α-aminoketone compound include: Examples include 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropan-1-one, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1-one, and the like. be able to.
These acetophenone compounds can be used alone or in admixture of two or more.
In the present invention, by using an acetophenone-based compound as another polymerization initiator, it is possible to further improve the sensitivity, the shape of the obtained spacer, the compressive strength, and the like.

Specific examples of the biimidazole compound include, for example,
2,2′-bis (2-chlorophenyl) -4,4 ′, 5,5′-tetrakis (4-ethoxycarbonylphenyl) -1,2′-biimidazole,
2,2′-bis (2-bromophenyl) -4,4 ′, 5,5′-tetrakis (4-ethoxycarbonylphenyl) -1,2′-biimidazole,
2,2′-bis (2-chlorophenyl) -4,4 ′, 5,5′-tetraphenyl-1,2′-biimidazole,
2,2′-bis (2,4-dichlorophenyl) -4,4 ′, 5,5′-tetraphenyl-1,2′-biimidazole,
2,2′-bis (2,4,6-trichlorophenyl) -4,4 ′, 5,5′-tetraphenyl-1,2′-biimidazole,
2,2′-bis (2-bromophenyl) -4,4 ′, 5,5′-tetraphenyl-1,2′-biimidazole,
2,2′-bis (2,4-dibromophenyl) -4,4 ′, 5,5′-tetraphenyl-1,2′-biimidazole,
Examples include 2,2′-bis (2,4,6-tribromophenyl) -4,4 ′, 5,5′-tetraphenyl-1,2′-biimidazole.

Among the biimidazole compounds, 2,2′-bis (2-chlorophenyl) -4,4 ′, 5,5′-tetraphenyl-1,2′-biimidazole, 2,2′-bis (2, 4-dichlorophenyl) -4,4 ′, 5,5′-tetraphenyl-1,2′-biimidazole, 2,2′-bis (2,4,6-trichlorophenyl) -4,4 ′, 5 5′-tetraphenyl-1,2′-biimidazole and the like are preferable, and 2,2′-bis (2,4-dichlorophenyl) -4,4 ′, 5,5′-tetraphenyl-1, is particularly preferable. 2'-biimidazole.
The biimidazole compounds can be used alone or in admixture of two or more.
By using these biimidazole compounds, sensitivity, resolution, and adhesion can be further improved.

In addition, when a biimidazole compound is used as another polymerization initiator, an aromatic compound having a dialkylamino group (hereinafter referred to as “dialkylamino group-containing sensitizer”) is used in combination to sensitize it. Can do.
Examples of the dialkylamino group-containing sensitizer include 4,4′-bis (dimethylamino) benzophenone, 4,4′-bis (diethylamino) benzophenone, ethyl p-dimethylaminobenzoate, ethyl p-diethylaminobenzoate, Examples include i-amyl p-dimethylaminobenzoate and i-amyl p-diethylaminobenzoate.
Of these dialkylamino group-containing sensitizers, 4,4′-bis (diethylamino) benzophenone is preferred.
The dialkylamino group-containing sensitizer can be used alone or in admixture of two or more.
The amount of the dialkylamino group-containing sensitizer used is preferably 0.1 to 50 parts by weight, more preferably 1 to 20 parts by weight with respect to 100 parts by weight of the copolymer [A]. In this case, if the amount of the dialkylamino group-containing sensitizer used is less than 0.1 parts by weight, the resulting spacer may be slipped or the pattern shape may be impaired, while 50 parts by weight. If it exceeds, the pattern shape of the spacer may be impaired.

  Furthermore, when a biimidazole compound and a dialkylamino group-containing sensitizer are used in combination as other polymerization initiators, a thiol compound can be added as a hydrogen donor compound. A biimidazole compound is sensitized and cleaved by a dialkylamino group-containing sensitizer to generate an imidazole radical, but at this time, high polymerization initiating ability is not necessarily expressed, and the obtained spacer has a reverse taper shape. In many cases, such an undesirable shape is obtained. This problem can be alleviated by adding a thiol compound to a system in which a biimidazole compound and a dialkylamino group-containing sensitizer coexist. That is, the hydrogen radical is donated to the imidazole radical from the thiol compound, so that the imidazole radical becomes a neutral imidazole and a component having a sulfur radical having a high polymerization initiating ability is generated. It becomes a shape.

Examples of the thiol compound include aromatics such as 2-mercaptobenzothiazole, 2-mercaptobenzoxazole, 2-mercaptobenzimidazole, 2-mercapto-5-methoxybenzothiazole, 2-mercapto-5-methoxybenzimidazole. Aliphatic monothiols such as thiols, 3-mercaptopropionic acid, methyl 3-mercaptopropionate, ethyl 3-mercaptopropionate, and octyl 3-mercaptopropionate. Examples of the bifunctional or higher aliphatic thiol include 3,6-dioxa-1,8-octanedithiol, pentaerythritol tetra (mercaptoacetate), pentaerythritol tetra (3-mercaptopropionate), and the like.
These thiol compounds can be used alone or in admixture of two or more.

The use ratio of the thiol compound is preferably 0.1 to 50 parts by weight, more preferably 1 to 20 parts by weight with respect to 100 parts by weight of the copolymer [A]. In this case, when the amount of the thiol compound used is less than 0.1 parts by weight, the resulting spacer tends to suffer from film slippage or a defective pattern shape, while when it exceeds 50 parts by weight, the spacer pattern shape is impaired. There is a risk of being.

Further, as the radiation-sensitive cationic polymerization initiator, onium salts such as phenyldiazonium tetrafluoroborate, phenyldiazonium hexafluorophosphonate, phenyldiazonium hexafluoroarsenate, phenyldiazonium trifluoromethanesulfonate, phenyldiazonium trifluoroacetate, phenyldiazonium- p-toluenesulfonate, 4-methoxyphenyldiazonium tetrafluoroborate, 4-methoxyphenyldiazonium hexafluorophosphonate, 4-methoxyphenyldiazonium hexafluoroarsenate, 4-methoxyphenyldiazonium trifluoromethanesulfonate, 4-methoxyphenyldiazoniumtri Fluoroacetate, 4-methoxypheny Diazonium-p-toluenesulfonate, 4-ter-butylphenyldiazonium tetrafluoroborate, 4-ter-butylphenyldiazonium hexafluorophosphonate, 4-ter-butylphenyldiazonium hexafluoroarsenate, 4-ter-butylphenyldiazonium trifluoro Diazonium salts such as romethanesulfonate, 4-ter-butylphenyldiazonium trifluoroacetate, 4-ter-butylphenyldiazonium-p-toluenesulfonate; triphenylsulfonium tetrafluoroborate, triphenylsulfonium hexafluorophosphonate, triphenylsulfonium Hexafluoroarsenate, triphenylsulfonium trifluoromethanesulfonate, Phenylsulfonium trifluoroacetate, triphenylsulfonium-p-toluenesulfonate, 4-methoxyphenyldiphenylsulfonium tetrafluoroborate, 4-methoxyphenyldiphenylsulfonium hexafluorophosphonate, 4-methoxyphenyldiphenylsulfonium hexafluoroarsenate, 4-methoxy Phenyldiphenylsulfonium trifluoromethanesulfonate, 4-methoxyphenyldiphenylsulfonium trifluoroacetate, 4-methoxyphenyldiphenylsulfonium-p-toluenesulfonate, 4-phenylthiophenyldiphenyltetrafluoroborate, 4-phenylthiophenyldiphenylhexafluorophosphonate 4-phenylthiophenyl dipheny Hexafluoroarsenate, 4-phenylthiophenyldiphenylsulfonium trifluoromethane sulfonate, 4-phenylthiophenyldiphenylsulfonium trifluoroacetate, sulfonium salts such as 4-phenylthiophenyldiphenylsulfonium -p- toluenesulfonate.
Examples of the metallocene compounds include (1-6-η-cumene) (η-cyclopentadienyl) iron (1+) hexafluorophosphate (1-).
Commercially available products of these radiation-sensitive cationic polymerization initiators include, for example, Adeka Ultra Set PP-33 (made by Asahi Denka Kogyo Co., Ltd.) which is a diazonium salt, OPTOMER SP-150 and 170 (both Asahi Denka) which are sulfonium salts. Kogyo Co., Ltd.) and Irgacure 261 (Ciba Specialty Chemicals Co., Ltd.), which is a metallocene compound.
Said radiation sensitive polymerization initiator can be used individually or in mixture of 2 or more types.

  In the photosensitive resin composition (A), the use ratio of the other photopolymerization initiator is preferably 100 parts by weight or less, more preferably 80 parts by weight or less, particularly preferably 100 parts by weight of the total photopolymerization initiator. Is 60 parts by weight or less. In this case, if the use ratio of the other photopolymerization initiator exceeds 100 parts by weight, the intended effect of the present invention may be impaired.

-Additives-
In the photosensitive resin composition (A), additives other than the above components can be blended as necessary within the range not impairing the intended effect of the present invention.
For example, in order to improve applicability, a surfactant can be blended. As the surfactant, a fluorine-based surfactant and a silicone-based surfactant can be suitably used.
As the fluorosurfactant, a compound having a fluoroalkyl or fluoroalkylene group in at least one of the terminal, main chain and side chain can be suitably used. Specific examples thereof include 1,1,2 , 2-tetrafluorooctyl (1,1,2,2-tetrafluoropropyl) ether, 1,1,2,2-tetrafluorooctyl hexyl ether, octaethylene glycol di (1,1,2,2-tetrafluoro) Butyl) ether, hexaethylene glycol (1,1,2,2,3,3-hexafluoropentyl) ether, octapropylene glycol di (1,1,2,2-tetrafluorobutyl) ether, hexapropylene glycol di ( 1,1,2,2,3,3-hexafluoropentyl) ether, sodium perfluorododecyl sulfonate, 1,1,2,2,8,8,9,9,1 , 10-decafluorododecane, 1,1,2,2,3,3-hexafluorodecane, sodium fluoroalkylbenzenesulfonate, sodium fluoroalkylphosphonate, sodium fluoroalkylcarboxylate, fluoroalkylpolyoxyethylene ether, diglycerin Examples thereof include tetrakis (fluoroalkyl polyoxyethylene ether), fluoroalkyl ammonium iodide, fluoroalkyl betaine, fluoroalkyl polyoxyethylene ether, perfluoroalkyl polyoxyethanol, perfluoroalkyl alkoxylate, and fluorine-based alkyl ester. .

Examples of these commercially available products include BM-1000, BM-1100 (manufactured by BM CHEMIE), MegaFuck F142D, F172, F173, F183, F178, F191, F191, F471, and F476. (Above, manufactured by Dainippon Ink & Chemicals, Inc.), Florard FC 170C, FC-171, FC-430, FC-431 (above, manufactured by Sumitomo 3M), Surflon S-112, S-113, S-131, S-141, S-145, S-382, SC-101, SC-102, SC-103, SC-104, SC-105, SC-106 ( Asahi Glass Co., Ltd.), Ftop EF301, 303, 352 (above, Shin-Akita Kasei Co., Ltd.), Footent FT-100, FT-11 FT-140A, FT-150, FT-250, FT-251, FTX-251, FTX-218, FT-300, FT-310, FT-400S ) Manufactured by Neos).
Examples of the silicone-based surfactant include Torre Silicone DC3PA, DC7PA, SH11PA, SH21PA, SH28PA, SH29PA, SH30PA, SH-190, SH-193, SZ-6032, SF -8428, DC-57, DC-190 (above, manufactured by Toray Dow Corning Silicone Co., Ltd.), TSF-4440, TSF-4300, TSF-4445, TSF-4446, TSF-4460, TSF-4442 (The above-mentioned, GE Toshiba Silicone Co., Ltd. product) etc. can be mentioned what is marketed.

  Examples of surfactants other than the above include polyoxyethylene alkyl ethers such as polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene oleyl ether; polyoxyethylene n-octylphenyl ether, polyoxy Polyoxyethylene aryl ethers such as ethylene n-nonylphenyl ether; nonionic surfactants such as polyoxyethylene dialkyl esters such as polyoxyethylene dilaurate and polyoxyethylene distearate, and commercially available products such as KP341 (Shin-Etsu) Chemical Industry Co., Ltd.), Polyflow No. 57, 95 (manufactured by Kyoeisha Yushi Chemical Co., Ltd.) and the like.

These surfactants can be used alone or in admixture of two or more.
The blending amount of the surfactant is preferably 5 parts by weight or less, and more preferably 2 parts by weight or less with respect to 100 parts by weight of the copolymer [A]. In this case, when the compounding amount of the surfactant exceeds 5 parts by weight, there is a tendency that film roughening is likely to occur during coating.

Moreover, in order to further improve the adhesion to the substrate, an adhesion assistant can be blended.
As the adhesion assistant, a functional silane coupling agent is preferable, and examples thereof include a silane coupling agent having a reactive functional group such as a carboxyl group, a methacryloyl group, an isocyanate group, an epoxy group, More specifically, trimethoxysilylbenzoic acid, γ-methacryloyloxypropyltrimethoxysilane, vinyltriacetoxysilane, vinyltrimethoxysilane, γ-isocyanatopropyltriethoxysilane, γ-glycidoxypropyltrimethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane and the like can be mentioned.
These adhesion assistants can be used alone or in admixture of two or more.
The compounding amount of the adhesion assistant is preferably 20 parts by weight or less, more preferably 10 parts by weight or less with respect to 100 parts by weight of the copolymer [A]. In this case, when the blending amount of the adhesion assistant exceeds 20 parts by weight, there is a tendency that a development residue is likely to occur.

Other additives can be added. It is added for the purpose of improving storage stability. Specific examples include sulfur, quinones, hydroquinones, polyoxy compounds, amines, and nitronitroso compounds. Examples thereof include 4-methoxyphenol and N-nitroso-N-phenylhydroxylamine aluminum. These are preferably used in an amount of 3.0 parts by weight or less, more preferably 0.001 to 0.5 parts by weight with respect to 100 parts by weight of the copolymer [A]. When the amount exceeds 3.0 parts by weight, sufficient sensitivity cannot be obtained, and the pattern shape deteriorates.
In order to improve heat resistance, an N- (alkoxymethyl) glycoluril compound, an N- (alkoxymethyl) melamine compound, and a compound having a bifunctional or higher functional epoxy group in one molecule can be added. Specific examples of the N- (alkoxymethyl) glycoluril compound include N, N, N, N-tetra (methoxymethyl) glycoluril, N, N, N, N-tetra (ethoxymethyl) glycoluril, N, N, N, N-tetra (n-propoxymethyl) glycoluril, N, N, N, N-tetra (i-propoxymethyl) glycoluril, N, N, N, N-tetra (n-butoxymethyl) glycol Examples include uril, N, N, N, N-tetra (t-butoxymethyl) glycoluril and the like. Of these, N, N, N, N-tetra (methoxymethyl) glycoluril is particularly preferable. Specific examples of the N- (alkoxymethyl) melamine compound include N, N, N, N, N, N-hexa (methoxymethyl) melamine, N, N, N, N, N, N-hexa (ethoxymethyl). ) Melamine, N, N, N, N, N, N-hexa (n-propoxymethyl) melamine, N, N, N, N, N, N-hexa (i-propoxymethyl) melamine, N, N, N , N, N, N-hexa (n-butoxymethyl) melamine, N, N, N, N, N, N-hexa (t-butoxymethyl) melamine and the like. Of these, N, N, N, N, N, N-hexa (methoxymethyl) melamine is particularly preferable. Examples of these commercially available products include Nicalac N-2702, MW-30M (manufactured by Sanwa Chemical Co., Ltd.) and the like.
Examples of compounds having two or more functional epoxy groups in one molecule include ethylene glycol diglycidyl ether, diethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, tripropylene glycol diglycidyl ether, and polypropylene glycol diglycidyl. Examples include ether, neopentyl glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, glycerin diglycidyl ether, trimethylolpropane triglycidyl ether, hydrogenated bisphenol A diglycidyl ether, and bisphenol A diglycidyl ether. Specific examples of these commercially available products include Epolite 40E, Epolite 100E, Epolite 200E, Epolite 70P, Epolite 200P, Epolite 400P, Epolite 40E, Epolite 1500NP, Epolite 1600, Epolite 80MF, Epolite 100MF, Epolite 4000, Epolite 3002 (and more) Chemical Co., Ltd.). These can be used alone or in combination of two or more.

Composition solution The photosensitive resin composition (A) is usually dissolved in a suitable solvent with constituent components such as a copolymer [A], a polymerizable compound [B], and a photopolymerization initiator [C]. Then, it is prepared as a composition solution.
As a solvent used for the preparation of the composition solution, a solvent that uniformly dissolves each component constituting the photosensitive resin composition (A) and does not react with each component is used.
As such a solvent, the thing similar to what was illustrated as a solvent which can be used in order to manufacture copolymer [A] mentioned above can be mentioned.

  Of these solvents, alcohols, glycol ethers, ethylene glycol alkyl ether acetates, esters and diethylene glycol are preferably used from the viewpoints of solubility of each component, reactivity with each component, ease of film formation, and the like. It is done. Among these, for example, benzyl alcohol, 2-phenylethyl alcohol, 3-phenyl-1-propanol, ethylene glycol monobutyl ether acetate, diethylene glycol monoethyl ether acetate, diethylene glycol diethyl ether, diethylene glycol ethyl methyl ether, diethylene glycol dimethyl ether, propylene glycol monomethyl ether Propylene glycol monomethyl ether acetate, methyl methoxypropionate, and ethyl ethoxypropionate can be particularly preferably used.

Furthermore, in order to improve the in-plane uniformity of the film thickness together with the solvent, a high boiling point solvent can be used in combination. Examples of the high boiling point solvent that can be used in combination include N-methylformamide, N, N-dimethylformamide, N-methylformanilide, N-methylacetamide, N, N-dimethylacetamide, N-methylpyrrolidone, dimethylsulfoxide, and benzylethyl ether. , Dihexyl ether, acetonyl acetone, isophorone, caproic acid, caprylic acid, 1-octanol, 1-nonanol, benzyl acetate, ethyl benzoate, diethyl oxalate, diethyl maleate, γ-butyrolactone, ethylene carbonate, propylene carbonate, phenyl Examples include cellosolve acetate. Of these, N-methylpyrrolidone, γ-butyrolactone, and N, N-dimethylacetamide are preferable.
The composition solution prepared in this way can be used for use after filtration through a Millipore filter having a pore size of, for example, about 0.2 to 0.5 μm, if necessary.

  The photosensitive resin composition (A) is particularly suitable as a material for forming spacers for display panels such as liquid crystal panels and touch panels.

When forming a display panel spacer using the display panel spacer photosensitive resin composition (a), after applying the composition solution to the surface of the substrate, pre-baking to remove the solvent, the coating film Form.
As a coating method of the composition solution, for example, an appropriate method such as a spray method, a roll coating method, a spin coating method (spin coating method), a slit die coating method, a bar coating method, or an ink jet coating method can be employed. In particular, a spin coating method and a slit die coating method are preferable.
Moreover, although the conditions of prebaking differ also with the kind of each structural component, a mixture ratio, etc., it is normally about 1 to 15 minutes at 70-90 degreeC.
Next, the pre-baked coating film is exposed and polymerized through a mask having a predetermined pattern, and then developed with a developing solution, and unnecessary portions are removed to form a pattern.
As radiation used for exposure, visible light, ultraviolet light, far ultraviolet light, charged particle beam, X-ray and the like can be appropriately selected, but radiation having a wavelength in the range of 190 to 450 nm is preferable.
As the developing method, for example, any of a liquid filling method, a dipping method, a shower method and the like may be used, and the developing time is usually 30 to 180 seconds.

Examples of the developer include inorganic alkalis such as sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, and ammonia; primary amines such as ethylamine and n-propylamine; Secondary amines such as n-propylamine; tertiary amines such as trimethylamine, methyldiethylamine, ethyldimethylamine and triethylamine; tertiary alkanolamines such as dimethylethanolamine, methyldiethanolamine and triethanolamine; pyrrole and piperidine , N-methylpiperidine, N-methylpyrrolidine, 1,8-diazabicyclo [5.4.0] -7-undecene, 1,5-diazabicyclo [4.3.0] -5-nonene 3 Secondary amines: pyridine, collidine, ru Jin, aromatic tertiary amines such as quinoline; tetramethylammonium hydroxide, the aqueous solution of an alkaline compound such as quaternary ammonium salts such as tetraethyl ammonium hydroxide may be used.
In addition, an appropriate amount of a water-soluble organic solvent such as methanol or ethanol and / or a surfactant can be added to the aqueous solution of the alkaline compound.
After development, for example, by washing with running water, for example, for 30 to 90 seconds, unnecessary portions are removed, and then compressed air or compressed nitrogen is blown to dry to form a predetermined pattern.
Thereafter, the pattern is heated by a heating device such as a hot plate or an oven at a predetermined temperature, for example, 150 to 250 ° C., for a predetermined time, for example, for 5 to 30 minutes on the hot plate, or for 30 to 90 minutes in the oven. By doing so, the target spacer can be obtained.

The photosensitive resin composition (I) of the present invention has a sufficient process margin, can suppress contamination of a baking furnace, a photomask, etc. due to sublimation of the photopolymerization initiator component, without causing foreign matter in the liquid, and It is a photosensitive resin composition for spacers capable of easily forming a spacer excellent in various properties such as cross-sectional shape, compressive strength, rubbing resistance, and adhesion to a transparent substrate.

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples and comparative examples. However, the present invention is not limited to these examples.
Synthesis example 1
A flask equipped with a condenser and a stirrer was charged with 7 parts by weight of 2,2′-azobis (2,4-dimethylvaleronitrile) and 200 parts by weight of propylene glycol monomethyl ether acetate. Subsequently, 20 parts by weight of styrene, 16 parts by weight of methacrylic acid, 18 parts by weight of tricyclo [5.2.1.0 ^2,6 ] decan-8-yl methacrylate, 40 parts by weight of 3- (methacryloyloxymethyl) -3-ethyloxetane. After the part was charged and purged with nitrogen, stirring was started gently. The temperature of the solution was raised to 70 ° C., and this temperature was maintained for 5 hours to obtain a polymer solution containing the copolymer [A-1]. The solid content concentration of the obtained polymer solution was 33.0%, and the weight average molecular weight of the polymer was 24,000 (weight average molecular weight was GPC (gel permeation chromatography) HLC-8020 ( It is a molecular weight in terms of polystyrene measured using Tosoh Corporation).

Synthesis example 2
A flask equipped with a condenser and a stirrer was charged with 7 parts by weight of 2,2′-azobis (2,4-dimethylvaleronitrile) and 200 parts by weight of propylene glycol monomethyl ether acetate. Subsequently, 20 parts by weight of styrene, 16 parts by weight of methacrylic acid, 18 parts by weight of tricyclo [5.2.1.0 ^2,6 ] decan-8-yl methacrylate, 3- (methacryloyloxymethyl) -2-trifluoromethyloxetane After 40 parts by weight were charged and purged with nitrogen, stirring was started gently. The temperature of the solution was raised to 70 ° C., and this temperature was maintained for 5 hours to obtain a polymer solution containing the copolymer [A-2]. The solid content concentration of the obtained polymer solution was 33.0%, and the weight average molecular weight of the polymer was 23,200 (weight average molecular weight was GPC (gel permeation chromatography) HLC-8020 ( It is a molecular weight in terms of polystyrene measured using Tosoh Corporation).

Synthesis example 3
A flask equipped with a condenser and a stirrer was charged with 7 parts by weight of 2,2′-azobis (2,4-dimethylvaleronitrile) and 200 parts by weight of propylene glycol monomethyl ether acetate. Subsequently, 20 parts by weight of styrene, 16 parts by weight of methacrylic acid, 18 parts by weight of tricyclo [5.2.1.0 ^2,6 ] decan-8-yl methacrylate, 40 parts by weight of 3- (methacryloyloxymethyl) -2-phenyloxetane. After the part was charged and purged with nitrogen, stirring was started gently. The temperature of the solution was raised to 70 ° C., and this temperature was maintained for 5 hours to obtain a polymer solution containing the copolymer [A-3]. The solid content concentration of the obtained polymer solution was 32.7%, and the weight average molecular weight of the polymer was 24,600 (weight average molecular weight was GPC (gel permeation chromatography) HLC-8020 ( It is a molecular weight in terms of polystyrene measured using Tosoh Corporation).

Synthesis example 4
A flask equipped with a condenser and a stirrer was charged with 7 parts by weight of 2,2′-azobis (2,4-dimethylvaleronitrile) and 200 parts of 3-methoxybutyl acetate, followed by 18 parts of methacrylic acid and tricyclomethacrylate. [5.2.1.0 ^2,6 ] 18 parts decan-8-yl, 5 parts styrene, 5 parts butadiene, 17 parts 3- (methacryloyloxymethyl) -3-ethyloxetane, tetrahydrofuran-2-yl methacrylate After charging 17 parts and purging with nitrogen, the temperature of the solution was raised to 80 ° C. while gently stirring, and this temperature was maintained for 5 hours to obtain a polymer solution containing the copolymer [A-4]. . The solid content concentration of the obtained polymer solution was 32.5%, and the weight average molecular weight of the polymer was 18,000 (weight average molecular weight was GPC (gel permeation chromatography) HLC-8020 ( It is a molecular weight in terms of polystyrene measured using Tosoh Corporation).

Synthesis example 5
A flask equipped with a condenser and a stirrer was charged with 5 parts by weight of 2,2′-azobis (2,4-dimethylvaleronitrile) and 200 parts by weight of diethylene glycol methyl ethyl ether, followed by 18 parts by weight of methacrylic acid and methacrylic acid. After charging 40 parts by weight of glycidyl, 5 parts by weight of styrene, and 32 parts by weight of tricyclo [5.2.1.0 ^2,6 ] decan-8-yl methacrylate, and substituting with nitrogen, 5 weights of 1,3-butadiene is further added. The temperature of the solution was raised to 70 ° C. while stirring gently, and the temperature was maintained for 5 hours for polymerization to obtain a solution of copolymer [A-5]. The solid content concentration of the obtained polymer solution was 33.3%, and the weight average molecular weight of the polymer was 20,000 (weight average molecular weight was GPC (gel permeation chromatography) HLC-8020 ( It is a molecular weight in terms of polystyrene measured using Tosoh Corporation).

Example 1
Preparation of Composition Solution 100 parts by weight (solid content) of the copolymer [A-1] obtained in Synthesis Example 1 as a copolymer [A], and KAYARAD DPHA (Nippon Kayaku) as a polymerizable compound [B] 80 parts by weight, 1- [9-ethyl-6- (2-methylbenzoyl) -9.H.-carbazol-3-yl] -ethane-1-one oxime as photopolymerization initiator [C] After dissolving 5 parts by weight of O-acetate (CGI-242 manufactured by Ciba Specialty Chemicals Co., Ltd.) in propylene glycol monomethyl ether acetate so that the solid content concentration is 30% by weight, it is filtered with a Millipore filter having a pore diameter of 0.2 μm. The composition solution (S-1) was prepared by filtration.

(I) Formation of Spacer The above composition solution was applied on an alkali-free glass substrate using a spinner and then pre-baked on a hot plate at 90 ° C. for 3 minutes to form a coating film having a thickness of 4.0 μm.
The coating film obtained above was exposed to ultraviolet rays having an exposure gap at a wavelength of 365 nm of 300 W / m ² with an exposure gap of 150 μm through a mask having a 10 μm square pattern. Next, development was performed with a 0.05 wt% aqueous solution of potassium hydroxide at 25 ° C. for 60 seconds, followed by rinsing with pure water for 1 minute. Furthermore, it heated at 150 degreeC for 120 minute (s) in oven, and the spacer was formed.

(II) Evaluation of resolution When the pre-baking temperature in (I) is different from 80, 90, and 100 ° C., in the obtained pattern, the case where the extraction pattern is resolved can be resolved. When there was no time, it was set as x.

(III) Sensitivity Evaluation In the pattern obtained in (I) above, if the sensitivity at which the residual film ratio after development is 90% or more is 1500 J / m ² or less, it can be said that the sensitivity is good.

(IV) Evaluation of pattern cross-sectional shape As a result of observing the cross-sectional shape of the pattern obtained in the above (I) with a scanning electron microscope, it showed which shape of A to C shown in FIG. . When the pattern edge is forward tapered as in A, the pattern shape is good. When the pattern edge is formed in a vertical shape as in B, the pattern shape is slightly good.
In addition, as shown in C, the shape that is inversely tapered (in which the side of the film surface in the cross-sectional shape is longer than the side on the substrate side, the inverted triangle shape) is likely to cause the pattern to peel off during the subsequent rubbing process. Therefore, such a shape was regarded as defective.

(V) Evaluation of rubbing resistance AL3046 (manufactured by JS R. Co., Ltd.) as a liquid crystal aligning agent was applied to the substrate obtained in the above (I) by a printing machine for applying a liquid crystal alignment film, and 1 at 180 ° C. It dried for a time and formed the coating film of the orientation agent with a dry film thickness of 0.05 micrometer.
The coating film was rubbed with a rubbing machine having a roll around which a nylon cloth was wound at a roll rotation speed of 500 rpm and a stage moving speed of 1 cm / sec. Table 2 shows the presence or absence of scraping or peeling of the spacer pattern.

(VI) Evaluation of adhesiveness Except not using a pattern mask, it carried out similarly to said (I), formed the cured film for adhesiveness evaluation, and performed the adhesiveness test. The test method followed the cross-cut tape method of 8.5.2 in the adhesion test of JIS K-5400 (1900) 8.5. Table 2 shows the number of the remaining grids.

(VII) Evaluation of Storage Stability The rate of change in viscosity when the radiation-sensitive resin composition was left in a constant temperature layer at 40 ° C. for 1 week was measured. Storage stability is good when the rate of increase in viscosity is less than 5%, and storage stability is poor when it is 5% or more.

(VIII) Evaluation of heat-resistant dimensional stability In the above (I), the thin film pattern formed at a pre-baking temperature of 80 ° C. was heated in an oven at 250 ° C. for 60 minutes. The dimensional change rate of the film thickness at this time is shown in Table 2. When the dimensional change rate is within 5% before and after heating, the heat-resistant stability is good, and when it exceeds 5%, the heat-resistant dimensional stability is poor.

(IX) Evaluation of sublimation property The composition solution was applied onto a substrate and then dried to form a film having a thickness of 6.0 μm. Then, for this coating, using n-octane as a standard substance (specific gravity = 0.701, injection amount; 0.02 μl), purging conditions at 100 ° C./10 minutes, headspace gas chromatography / mass Analysis (headspace sampler: JHS-100A manufactured by Nippon Analytical Industries, Ltd., gas chromatography / mass spectrometer; JEOL JMS-AX505W type mass spectrometer), peak area A derived from radiation-sensitive polymerization initiator And the amount of volatilization in terms of n-octane was calculated by the following formula. It can be said that the greater the volatilization amount, the greater the sublimation property.
Calculation formula of volatilization amount in terms of n-octane Volatilization amount (μg) = A × (amount of n-octane) (μg) / (peak area of n-octane)

(X) Evaluation of foreign matter in liquid The presence or absence of a recrystallized product of the radiation-sensitive polymerization initiator component in which the composition solution was stored at −15 ° C. for 7 days was visually observed. Further, when the liquid temperature of the stored composition solution is raised from −15 ° C. to 23 ° C., a solid matter (residual foreign matter) having a size of 0.5 μm or more remaining without being redissolved in 1 ml of the composition solution. ) Was measured using a light scattering submerged particle detector (KS-28B, manufactured by Rion Co., Ltd.).

Examples 2-10, Comparative Examples 1-3
In Example 1, a composition solution was prepared and a spacer was formed in the same manner as in Example 1, except that the types and amounts shown in Table 1 were used as the components [A] to [C]. And evaluated. The addition amount of [B]-[C] is a weight ratio with respect to 100 parts by weight of the copolymer [A].
In Table 1, the abbreviations of the components indicate the following compounds.
(B-1): KAYARAD DPHA (manufactured by Nippon Kayaku Co., Ltd.)
(B-2): KAYARAD DPHA-40H (manufactured by Nippon Kayaku Co., Ltd.)
(C-1): 2- (4-methylbenzyl) -2- (dimethylamino) -1- (4-morpholinophenyl) -butan-1-one (Irgacure 379 manufactured by Ciba Specialty Chemicals),
(C-2): 1- [9-ethyl-6- (2-methylbenzoyl) -9.H.-carbazol-3-yl] -ethane-1-one oxime-O-acetate (Ciba Specialty Chemicals) CGI-242)
(C-3): 1,2-octadion-1- [4- (phenylthio) phenyl] -2- (O-benzoyloxime) (CGI-124 manufactured by Ciba Specialty Chemicals)

(C-4): 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropan-1-one (Irgacure 907 manufactured by Ciba Specialty Chemicals)
(C-5): 2,2′-bis (2-chlorophenyl) -4,4 ′, 5,5′-tetraphenyl-1,2′-biimidazole (C-6): 4,4′-bis (Diethylamino) benzophenone (C-7): 2-mercaptobenzothiazole (C-8): 2-benzyl-2- (dimethylamino) -1- (4-morpholinophenyl) -butan-1-one (Ciba Specialty Chemicals Irgacure 369)
In Table 1,-indicates that the component is not added.
The evaluation results are shown in Table 2.

It is a figure which illustrates the cross-sectional shape of a pattern.

Claims (5)

[A] (a1) unsaturated carboxylic acid and / or unsaturated carboxylic acid anhydride,
(A2) a monomer represented by the following general formula (I) or general formula (II),

[Wherein, R in the general formulas (I) and (II) is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms; R ₁ is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms; ₂ , R ₃ , R ₄ and R ₅ are each independently a hydrogen atom, a fluorine atom, an alkyl group having 1 to 4 carbon atoms, a phenyl group, or a perfluoroalkyl group having 1 to 4 carbon atoms, and n is 1 It is an integer of ~ 6. ]
And
(A3) a copolymer of an ethylenically unsaturated compound other than (a1) and (a2),
[B] A photosensitive resin composition comprising a polymerizable compound having an ethylenically unsaturated bond, and [C] a photopolymerization initiator having a compound represented by the following general formula (III) as an essential component object.

[In the general formula (III), R ₆ represents a linear, branched or cyclic alkyl group having 1 to 12 carbon atoms, R ₇ and R ₈ are independently a hydrogen atom; A linear, branched or cyclic alkyl group or a benzyl group, wherein R ₉ , R ₁₀ , R ₁₂ and R ₁₃ are each independently a hydrogen atom; a halogen atom; a linear or branched group having 1 to 12 carbon atoms A linear or branched alkyl group having 1 to 4 carbon atoms or a linear or branched alkoxyl group having 1 to 4 carbon atoms, and R ₁₁ is a halogen atom; a linear, branched or cyclic alkyl group having 1 to 12 carbon atoms; A linear, branched or cyclic alkyl group having 1 to 12 carbon atoms substituted with a substituent selected from the group consisting of a hydroxyl group and a linear or branched alkoxyl group having 1 to 4 carbon atoms; 4 linear or branched al It shows the or hydroxyl and straight-chain or branched straight-chain or branched alkoxy group having 2 to 4 carbon atoms which is substituted with a substituent selected from the group of alkoxy group having 1 to 4 carbon atoms; cyclohexyl group. ] The photosensitive resin composition of Claim 1 used for formation of the spacer for liquid crystal display panels. The spacer for liquid crystal display panels formed from the photosensitive resin composition of Claim 2. A method for forming a spacer for a liquid crystal display panel, comprising at least the following steps in the order described below.
(A) forming a film of the photosensitive resin composition according to claim 2 on a substrate;
(B) exposing at least a part of the coating;
(C) a step of developing the coated film after exposure, and (d) a step of heating the coated film after development. A liquid crystal display panel comprising the spacer according to claim 3.

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